An Iowa Democratic Senate candidate’s dismissal of Sen. Chuck Grassley (R., Iowa) as a “farmer from Iowa who never went to law school” has rallied Republicans, drawing national attention — and funds — to the Senate race.

The conservative Priorities for Iowa launched a $250,000 ad campaign called “Not For Sale,” accusing Democratic Rep. Bruce Braley of “putting Iowa’s Senate seat up for sale.” With eerie music and a horror-style green tint overlaying the image, the ad portrays the congressman as shady and corrupt. “Caught at a closed-door fundraiser with trial lawyers in Texas, Braley says if they don’t help him, Chuck Grassley … might be the next Senate Judiciary Committee Chairman.”

Mr. Braley, a former president of the Iowa Trial Lawyers Association, made the comment as he addressed a group of trial lawyers at a Texas fundraiser, a video of which was posted Tuesday by the conservative America Rising PAC.

“Tell Bruce Braley that we’d rather bet the farm on Grassley than a bunch of trial lawyers from Texas,” the ad concludes. The 30-second clip will run statewide on TV and online. The group also uploaded a picture of George Washington on its Facebook page with the caption, “If only he had gone to law school – He could have really been somebody!”

The National Republican Senatorial Committee also on Thursday launched robocalls to 305,000 Iowa households, targeting Mr. Braley for “insulting Iowa farmers.” The call plays a recording of Mr. Braley’s remarks at the Texas fundraiser, and offers recipients the option of being connected to the congressman’s office to tell him that “a law degree doesn’t equal success.”

The Quad-City Times, an Iowa paper, published an editorial Thursday saying Mr. Braley is guilty of a “disastrous campaign strategy” more than anything else. “In an Iowa popularity contest, trial lawyer wouldn’t even get honorable mention versus a farmer.”

Mr. Braley apologized on Tuesday, but that hasn’t stopped Republicans from hitting back. Mark Jacobs, the leading Republican challenger, released a radio ad Wednesday bashing Mr. Braley, and Iowa state Sen. Joni Ernst, who’s also vying for the Republican nomination, released a statement calling the congressman “out of touch.”

For the six Iowa Republicans running for the Senate nomination, the Braley commotion could give a boost to whoever wins the June 3 primary. One hitch: If no candidate gets more than 35% of the primary vote, a convention will pick the GOP candidate.

The endorsements are rolling in. Former Alaska Gov. Sarah Palin took to Facebook Wednesday to endorse Ms. Ernst, praising her “pork cutting” skills. (Ms. Ernst had Tuesday released an ad entitled “Squeal,” which opens with the line: “I grew up castrating hogs on an Iowa farm. So when I get to Washington, I’ll know how to cut pork.”)

The conservative Citizens United Political Victory Fund endorsed conservative radio host Sam Clovis Thursday, calling him the “only principled conservative in the race.” Former GOP presidential candidate Mitt Romney endorsed the state senator earlier this month.

One glimmer of hope for Mr. Braley, who has held a double-digit lead over most Republican challengers, came in a fundraising email from the left-leaning Progressive Change Campaign Committee. The email, from Sen. Elizabeth Warren(D., Mass.), endorsed Mr. Braley and Democrat Rick Weiland in the North Dakota Senate race, calling them “smart, experienced, bold progressives.”

The email said Mr. Braley is “focused on economic fairness, investing in education, and addressing our retirement crisis” and urges readers to make a donation. It didn’t mention his farmer remark.

Here is Iowa state Sen. Joni Ernst’s “Squeal” video in which she touts the “pork-cutting” skills that prompted former Gov. Sarah Palin to endorse her:

About Washington Wire

Washington Wire is one of the oldest standing features in American journalism. Since the Wire launched on Sept. 20, 1940, the Journal has offered readers an informal look at the capital. Now online, the Wire provides a succession of glimpses at what’s happening behind hot stories and warnings of what to watch for in the days ahead. The Wire is led by Reid J. Epstein, with contributions from the rest of the bureau. Washington Wire now also includes Think Tank, our home for outside analysis from policy and political thinkers.